Molly Ringwald isn't logging much sleep these days – and she couldn't be more delighted about it.

"You get up with one of the babies and feed and change that one and get the baby back to sleep, and the other wakes up, and then you feed and change that one," the star of '80s classics Pretty in Pink and Sixteen Candles says of her nocturnal routine since the July 10 arrival of her twin son and daughter, Roman Stylianos and Adele Georgiana.

"It is exhausting, but it's wonderful," the actress, 41, tells PEOPLE in its new issue.

The twins join big sister Mathilda, 5 ½, and dad Panio Gianopoulos, 34, whom Ringwald married in 2007. "After Mathilda was born, I had some things fixed" – surgery to remove fibroids – "that made it easier to get pregnant again," says Ringwald.

Ringwald, whose pregnancy was written into her ABC Family series The Secret Life of the American Teenager, calls the twins' birth "extraordinary. The doctor grabbed [Roman] by the foot and pulled him out. Adele had hogged a lot of the oxygen in the blood so right away Roman needed a little more attention. But both babies cried almost immediately."

For more on this story – and more pictures, too – pick up this week's issue of PEOPLE, on newsstands Friday